random selection

2011 10 30
3 个回答
回答已采纳
5 次查看（30 天）

0 个投票

I have a matrix size of 96x249.How can i select 48 rows randomly and store it into a new matrix of 48x249.I have values in matrix as decimal numbers.

请先登录，再回答此问题。

 采纳的回答

Walter Roberson
Walter Roberson 2011-10-30

2 个投票

T = randperm(96);
NewMatrix = OldMatrix(T(1:48),:);

2 个评论
显示 无 隐藏 无

Abhiya
Abhiya 2011-11-1
thanks for the answer.do i have an option to store the rest of the matrix after random selection?
Walter Roberson
Walter Roberson 2011-11-1
RestOfMatrix = OldMatrix(T(49:end),:);

请先登录，再进行评论。

更多回答（2 个）

Peter Perkins
Peter Perkins 2011-11-1

1 个投票

There are a number of ways to do this, including Walter's suggestion. But in addition, if you have access to MATLAB R2011b, there is the slightly simpler
NewMatrix = OldMatrix(randperm(96,48),:);
and if you have access to the Statistics Toolbox in R2011b, there is also
NewMatrix = datasample(OldMatrix,48);
The latter option also allows you to sample with weights, and with replacement. Of course, neither allows you to get the rest of the matrix.
Abhiya
Abhiya 2011-11-4

0 个投票

My heartful thanks to everybody

类别

在 帮助中心 和 File Exchange 中查找有关 Creating and Concatenating Matrices 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by